Tongues and Tastebuds

tongues headerIn 1901, german scientist Deiter Hanig conducted some taste research using volunteers. His results suggested that different areas of the tongue had different levels of sensitivity to different tastes.

His data was re-interpretted by scientists over the 20th century, in particular by Edwin Boring (real name!). Boring put this data together and from this the tongue map was born; a scientific diagram of where we sense which taste.


tongue map

Tongue map. Image: science made simple (CC-BY-NC)


But this is wrong!

Well, sort of. In fact, the original research now appears closer to the truth. The tongue map shows areas which are more sensitive to a particular taste, not the areas which exclusively recognise a taste.

So for example, we can still taste bitterness on the tip of our tongue, however we are more sensitive to it at the back of the tongue. Likewise, we can taste sweetness on the back as well as the front, but not as well.

If this weren’t true, then people who’ve lost the front of their tongues (it does happen) wouldn’t ever be able to taste sweet things.

There’s a theory that the tip of the tongue tastes bitterness at the back, because this is linked to a revulsion technique. If we encounter a bitter taste, usually this means we shouldn’t swallow whatever is in our mouth. It’s easier to create a muscular revulsion from the back of the mouth and the throat, rather than at the front. Plus, more saliva can be injected at the back of the mouth to douse the potential poison.

tongue vomit

Image: science made simple (CC-BY-NC)

Did you know that children have a higher sensitivity to sweet and bitter tastes than groan ups like me? This explains why children go ABSOLUTELY CRAZY* for sugar snacks and sweets.

*actual mother’s wordswhite_space

This also explains why children tend to find beer and ale repulsive too. Which is probably a good thing for society. Although our taste receptors do mellow over the years, we can also program our brain to believe that a ‘nasty’ taste is actually associated with good things, if we consume it often enough. This is what we refer to as an ‘acquired taste’, and it’s true for chilli and spices and pints of Guinness.

But what about some of the other tastes, that aren’t bitter and sweet? Well, saltiness is an interesting one. Our bodies need the NaCl goodness of salt to keep us ticking over, but equally too much salt can cause problems. It was recently discovered that our taste receptors have adapted to enjoy salt up to a point, and then to gradually become more repulsed as we consume too much, thus putting us off. Cool huh!

There is also a fifth taste, not included on the tongue map as it wasn’t really known about in the western world until fairly recently. We know it as Monosodium Glutomate, or MSG. However, the Japanese knew about this flavour many years before us, and called it ‘Umami’. It’s difficult to describe how it tastes, but you can easily buy some as a simple flavouring and try it for yourself.white_space

And with that our wonderful blog post on the tongues and tasting comes to an end. It’s important to remember though, this isn’t the easiest area of science to investigate, and while the tongue map is itself an over-simplification, there is still debate about how sensitive different taste receptors are. This isn’t helped by the fact that people are different, they live in different parts of the world, and eat different things. All this makes it hard to create any ‘normal’ model of taste!


Image: science made simple (CC-BY-NC)

We love the science of food! So much so that we’re currently writing our own science show for the public (that’s you), all about what we eat. We’re going to use foods in quite an unusual way, and see how the audience can help us demonstrate the science behind them.

So watch this space, and in the meantime check out all the other biology related blog posts we’re putting on throughout this week, in celebration of National Biology Week 2013. Hurrah!


sms group shot with props smallWe are science made simple, a social organisation which promotes science, maths and engineering in schools and to the public. You can find out more about what we do, book us live in action with one of our exciting shows, or sign up to our newsletter and find out what we’re up to!


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Posted in Biology